Direct positive photographic development process



Aug. 3, 1954 G. M. HAlsT r-:TAL

DIRECT POSITIVE PHOTOGRAPHIC DEVELOPMENT PROCESS Filed Aug. 3, 1955 GRA/vr M HA/sr HAROLD o. @USSL-LL INVENTORS` BY MM l rmi/jmd@ ATTORNEY a AGE/V7' Patented Aug. 3, 1954 UN TED ApplicetiohAugustB, 1953, Serial No. 3719946 T7 Claims. l This Iinvention relates to .a v.direct positive process lfor .th'efdevelopment of photographs `and -particularly fto methods for accelerating development 1in ka .direct ,positive process;

In the Ives U. S. Patent 2,563,785, August FI,

1951, and -the Bean etfal. Patent 2,604,400, July 22, 1952,'is described afproeess :for -the development of :direct `positive .images :an exposed :internal latent image emulsion .by 'use .of developer compositions containing Lhydrazine or certain hydrazine derivatives.

VWe .have ffound that the Adevelopment activity of hydrazinecontaining developers, 'particularly when 'they are used for `the development of .direct positive `images in anex-pesed internal latent image emulsion, is appreciabl-y acoeleratedfand the .useful life of Lthe developer composition is materially extended, Lif `certain :quaternary Aam'- monium compounds are incorporated into :the hydrazineontainingdeveloper.

The accompanying drawings illustrate the aocell-,ration of v.development obtained by :use -of certain Quaternary ammonium compounds in a developer composition for developing 1an internal latent image emulsion.

The effective quaternary ammonium -eompounds Lare as follows:

l NBr 2 benzyl-Bemeth-yl .isoquiholnium bromide lll 40 Sulfur sensitizeis.

l--phenethyl lepidinium bromide :Many otheriquaternary ammonium compounds have been found n'o't'ito :be :effective in 'accelerating development Lin sone pirocess kof our invention; for example', the following:

l.15 2methyl -benzoselenazole Vmethyl iodide Methyl benzotriazolium 1@toluene Nsul-fonate 6aminobenzothiazole dimethyl perchlorate l-benzyl-a-picolinium bromide l-benzyl-pieolinium bromide gn l-'benzyl-fyhpicolinium bromide l-phenethyl-vepicolinium bromide l--phenethyl quinaldinium bromide Dimethylene pyridinium perchlorate -Phenylethyl-picolinium bromide perchlorate N,N' ethylene dioxyme'thyl pyridinium perchloratey 30 rIhe photographic emulsion used in the proc- 35 sensitizing dyes although certain sensitizing dyes maybe added to it -for the .purpose of optical Sensitizing or forpromo'tihg reversal. 'The 'mulsion should-be undige'sted or -i'f digested, the digestion should be carried out Without :the use 'of An 'emulsion of this type is that known as Burtons emulsion, described in Wall, Photographic Emulsions, 1929, pages 52 and l53. Burt'oris emulsion 'is made as "followsf 45 A. Silver nitrate g I1.00 Water l :cc '500 'Ammoniato' 'forni felear solution.

B. =Potassiui'n bromide -g 280 i-Potas'siiuin iodide l, -g "50 ro Soft gelatin g M v20 0 Water cc-- 1,000

C. Dry lgelati-n Y g i250 B `is Iheated to '70 C. vand-A, zcold, :added to B with Iooi-istant shaking, digested for `20 minutes after being allowed to swell for 20 minutes in Water, drained and melted. The emulsion is then set and Washed.

An internal latent image emulsion, that is, one which forms the latent image mostly inside the silver halide grains, as described on pages 295 and 297 of Mess The Theory of the PhotographicProcess, 1942, is especially useful for the process of our invention.

Most of the internal latent image emulsions are silver bromoiodide emulsions of high iodide content, preferably containing at least %20% of the halide as iodide. Burtons emulsion is an emulsion of this type, having a silver iodide content of approximately 40% of the content of silver halide. It is not absolutely essential, however, for the emulsion to contain silver iodide.

An internal latent image emulsion made as described in Davey and Knott U. S. Patent No. 2,592,250, may also be used according to our invention. This emulsion is prepared by first forming in the absence of ammonia and in one or more stages, silver salt grains Iconsisting at least partly of asilver salt which is more soluble in Water than silver bromide, subsequently converting the grains to silver bromide or silver bromoiodide and if the silver iodide content of the emulsion is less than 6% calculated on the total silver halide, treating such grains with an iodine compound to bring the silver iodide up to at least 6%, ripening preferably in the absence of ammonia and then either Washing out some of the soluble salts or Washing out the Whole of the soluble salts, followed bythe addition of soluble salts such as soluble chloride or bromide. An example of an emulsion made in this Way is as follows:

Solution No. 1

Run Solutions Nos. 2 and 3 simultaneously into Solution No. l in a vessel, taking 90 seconds to do this. Then ripen for l minute at 45 C. Next add 235 grams of inert gelatin (dry). Then ripen at 45 C'. for l5 minutes during which time the gelatin dissolves. Set and shred the emulsion and then wash until free from all soluble bromide and then add about 150 cc. of 10% solution of KCl (by Weight) and then add Water to make 3% liters.

' An internal latentlimage type of silver halide emulsion may be defined as one which, when a test portion is exposed to a light intensity scale for a fixed time between V100 and l second, and developed for 4 minutes at 20 C. in the ordinary surface developer (Example I) exhibits a maxl- F mum density not greater than 1/5 the maximum density obtained when the same emulsion is equally exposed and developed for 3 minutes at C. in an internal type developer (Example Il). Preferably the maximum density obtained with the surface developer is not greater than 174,0 the maximum density obtained when the same emulsion is developed in the internal type developer. Stated conversely, an internal latent image emulsion, when developed in an internal type developer (Example Il) exhibits a maximum density at least 5, and preferably at least 10, times the maximum density obtained when the same emulsion is exposed in the same way and developed in a surface developer (Example I).

Our process is carried out by exposing the internal latent image emulsion layer to an object or image and then placing the exposed emulsion layer directly in a silver halide developing solution containing one or more hydrazines such as those mentioned hereinafter and in addition, containing one or more of the above-mentioned effective Quaternary ammonium compounds as well as developing agent. Alternately, the hydrazine can be incorporated into the internal latent image emulsion in which case the exposed emulsion layer is developed in a developer solution containing one or more of the mentioned effective Quaternary ammonium compounds as Well as a developing agent.

Developing agents suitable for use in the process of our invention include the usual phenolic or aminophenol type developing agents such as N-methyl-p-aminophenol sulfate, hydroquinone, catechol, 2-methyl hydroquinone, Z-chlorohydroquinone, p-aminophenol, and pyrogallol. Also, 3- pyrazolidone developing agents are veryy useful in our developer compositions, for example, 1 (p I3 hydroxyethylphenyl) 3- pyrazolidone, l phenyl- 3 pyrazolidone, 1 ptolyl 3 pyrazolidone, 1 phenyl 2 acetyl- S-pyrazolidone, and particularly the 1-aryl-4,4- dialkyl-S-pyrazolidones such as 1-phenyl-4,4-dimethyl 3 pyrazolidone, l (p--hydroxyethylphenyl) 4,4 dimethyl 3 pyrazolidone and 1 p tolyl 4,4 dimethyl 3 pyrazolidone described in Allen et al. U. S. patent application Serial No. 372,148 led August 3, 1953, and in the Reynolds and Tinker U. S. patent application Serial No. 372,167, filed August 3, 1953.

Particularly eficacious developer compositions are those containing, in addition to the indicated eifective Quaternary ammonium compounds, a mixture of developing agents such as a mixture of N-methyl-p-aminophenol and hydroquinone, or a mixture of lhydroquinone and a 3-pyrazolidone developing agent.

The hydrazines useful in the developer compositions include those partieularly described in the Thirtle et al. U. S. Patent 2,618,656, November 18, 1952, and in the Weissberger U. S. patent application Serial No. 159,139 filed April 29, 1950, now Patent No. 2,663,732, such as the following:

p Methylsulfonamidomethyl) -phenylhydrazine m- (Methylsulfonamidomethyl) -phenylhydrazine o (Methylsulfonamidomethyl) -phenylhydrazine p (-Methylsulfonamidoethyl) -phenylhydrazine rn- (-MethylsulfonamidoethyD -phenylhydrazine o (-Methylsulfonamidoethyl) -phenylhydrazine m- (Methylsulfonamido) -phenylhydrazine p- (Methylsulfonamido) -phenylhydrazine m- (Ethylsulfonamido) -phenylhydrazine p- (Ethylsulfonamido) -phenylhydrazine o- (Methylsulfonamido) -phenylhydrazine The a l ky l s ul f onamidoalkylphenylhydrazines and the alkylsulfonamidophenylhydracines are particularly useful since they possess low toxicity characteristics compared Ato most' of the other hydrazines. In addition thesenhydrazines in the presence of the culaternary` ammoniumA compounds are much more effective' inl maintain'- ing contrast than are other' hydrazines such-asf phenyl hydrazine, vnuclear-substituted phenylhydrazines and sulfonated naphthylhydrazines.

The' water-soluble salts of the hydrazines are, of

course, very useful' preparing the developer compositions.

Thesehydrazines have the'general formula:

An internal type developer, that is, onewhich.` develops an image inside the grains of 'an internal latent image emulsion is thefollowing:

Example II G. I-Iydroquinone n-lvethyl-p-aminophenol sulfate 15. Sodium sulte (anhydrous) 50i Potassium bromide 10 Sodium hydroxide Sodium thiosulfate (crystals) 20 Water to 1 liter. Development time, 3 min. at 20C.

Our invention will be further illustrated by reference to the following specic examples:

Example III An emulsion made asdescribed. inthe Davey and Knott application Serial No. 82,914 was coated on a support, dried and exposed on an intensity scale sensitometer tia-3000? Kelvin tung- Isten illumination` anddeveloped. for. from 1. toy 2. minutes at 75 F. ina solution', ofthe following composition:

G. N -methyl-p-aminophenol su1fate.. 5.0 Hy-droquinoneY 10.0 p- (,f3-Methylsulionamidoethyl).v phenyl hydrazine hydrochloride 2.0 Sodium sulte (desiccated) 75.0. Trisodium phosphate, cryst 75.0 Diglycolic acid 13.4 5methyl benzotriazole 0.2. Sodium hydroxide 15.0l

3-methy1-2-phenethylisoquinolinium.

bromide 0.4V to 0.6 Water to make 1.0 liter..

A satisfactory direct positive'image'was obtained under these developing conditions and the' developer compositions showed no adverse effects from oxidation.

The improvement in developing activity eiected by use offthe quaternary ammonium compound this' example is illustrated in the accompanying drawings wherein curves A, B and C showY thel appearance of the Dlog E curvesatdiiferent de*- velopment times when development' was conducted under the'abovecondition's withithe'above 6i developer composition to which quaternary ammoniumV compoundhad been added... Curves D, E andvF show that development-was.appreciably accelerated when it was. carried` out under` thel 5'- same conditions except for.. using the. Quaternary ammonium compound in the developer composition.

EampleIV Aportion of the emulshion used inExampl'eIlI.y

was coated and exposed as in. ExampleIII andi developed for 1 to 2 minutes at 75 F. in a solution of the following composition:

drazine hydrochloride 2.0 Hydroquinone 10.0 I-phenyl-S-pyrazolidone 0.5% Sodium suliite (desiccated) 75.01

202 5-methyl benzotriazole 0*.2L

mide Sodium hydroxide Water to 1.0 liter.

i dation. `I

Under these development conditionsaisatisfac-I tory directpositive image. was obtained and the: developer showed relatively. little sign` of ox-i-f Example V` A- portion of the. emulsion usedin llxamplevIIIA was coated and exposed as inExample III and. developed for 3 minutesat 75` F. in a solution. of the following composition:

drazine hydrochloride 2.0,' Hhydroquinone 10.0" n-Methyl-p-aminophenol sulfate 5.0. Sodium sullte (desiccated) 75.0 Sodium carbonate monohydrate 4010 Benzotriazole 012' 3-methyl-2--phenethyl isoquinolinium bromide Water 13o-make 1,0 liter.

Under these development conditions a satisfactory direct positive image was obtained and-theL developer showed no adverse signs" of oxidation effects.

Example VI A portion of the emulsion used in Example III was` coated and exposed as in Example III developed for 1 to 2 minutes at 75 F. in af solu tion of the following' composition:

p- (-Methylsulfonamidoethyl) phenylhyn drazihe hydrochloride 2.0.' Hydroquinone 1010 1-phenyll,et-dimetlfiyl'-3--pyrazolidonev 1.0 Sodium sulfite (desiccated) 75.0. 5-methyl benzotriazole 0.2. 3-methyl-2--phenethylisoquinolinium bromide 0.4 Sodium hydroxide. 6.7 Waterk to 1.0 liter. :911:-

Under these development conditions al satis# factory direct positive image was obtainedv and thedeveloper showedrelativelylittle signlof oxidation: l

Example VII A portion of the emulsion used in Example III was coated and exposed as in Example 111 and developed for 1 to 2 minutes at 75 F. in a solution of the following composition:

p- (,i-methylsulfonamidoethyl) phenylhydrazine hydrochloride 2.0 Hydroquinone 10.0

1-(4--hydroxyethylphenyl) 3 pyrazolidone 1.0 Sodium sulte (desiccated) 75.0 5-methy1benzotriazole 0.2

3-methyl-2-phenethylisoquinolinium bromide 0.4 Sodium hydroxide 6.7

Water to 1.0 liter. ph=11.5.

Under these development conditions a satisfactory direct positive image was obtained and the developer showed relatively little sign of oxidation.

An unexpected result of development, particularly by the methods of Examples IV, VI and V11, is that the developers remain cleaner and lighter in color and maintained their activity much longer than when the emulsion is developed with the same developer free oi the Quaternary ammonium compound. That is, the developers showed little coloration after several days intermittent use Whereas the control developer turned red in a few hours, orange overnight and black in 3 days. It is to be further noted that superior keeping properties of the developers can be expected when the S-pyrazolidone compounds are used in the developers in place of N-methyl-paminophenol.

It will be understood that the examples and modifications included herein are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

What we claim is:

1. A photographic developing composition comprising an aqueous alkaline solution containing a mixture of a silver halide developing agent, a compound selected from the group consisting or S-methyl-Z--phenethylisoquinolinium bromide, 2-benzyl-S-methyl-isoquinolinium bromide, l-,B- phenethyl-,B-picolinium bromide, l--phenethylquinolinium bromide and 1--phenethyl lepidinium bromide, and a hydrazine having the general formula wherein D represents a divalent mononuclear arylene group of the benzene series, n represents a positive integer of from 1 to 5, and R represent-s an alkyl group oi from 1 to 4 carbon atoms.

2. The photographic developer composition of claim 1 wherein the designated hydrazine has the general formula wherein D represents a divalent mononuclear arylene group of the benzene series and R represents an alkyl group oi from 1 to 4 carbon atoms.

3. The photographic developer composition of claim 1 wherein the designated developing agent is a S-pyrazolidone silver halide developing agent.

4. The photographic developer composition of claim 1 wherein the designated hydrazine is p-(- methylsulfonamidoethyl) -phenylhydrazine 5. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a silver halide developing agent, 3- methyl-2--phenethylisoquinolinium bromide, and a hydrazine having the general formula wherein D represents a divalent mononuclear arylene group of the benzene series, n represents a positive integer of from 1 to 5, and R represents an alkyl group of from 1 to 4 carbon atoms.

6. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and N-methyl-p-aininophenol silver halide developing agents, p-(- methylsulfonamidoethyl)phenylhydrazine, and 3-methyl-2--phenethylisoquinolinium bromide.

7. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and a B-pyrazolidone silver halide developing agent, p-(-methylsulionamidoethyl)phenylhydrazine, and S-methyl- 2-B-phenethylisoquinolinium bromide.

8. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and l-phenyl-S-pyrazolidone silver halide developing agents, p-(- methylsulfonamidoethyl)phenylhydrazine, and 3-methyl-Z--phenethylisoquinolinium bromide.

9. A photographic developer composition comprising an-aqueous alkaline solution containing a mixture of hydroquinone and 1-phenyl-/l,4- dimethyl-B-pyrazolidone silver halide developing agents, p- (-methylsulfonamidoethyl) phenylhydrazine, and 3-methyl-Z--phenethylisoquinolinium bromide.

10. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and 1-p-tolyl-4,4 dimethyl-B-pyrazolidone silver halide developing agents, p- ,S-methylsulfonamidoethyl) phenylhydrazine, and 3-methy1-2-phenethylisoquinolini um bromide.

11. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of a silver halide developing agent, 2- benzyl-S-methylisoquinolinium bromide, and a hydrazine having the general formula wherein D represents a divalent mononuclear arylene group of the benzene series, n represents a positive integer of from 1 to 5, and R represents an alkyl group of from 1 to 4 carbon atoms.

12. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and N-methyl-paminophenol silver halide developing agents, p- (-methylsulfonamidoethyl) phenylhydrazine and Z-benzyl-S-methylisoquinolinium bromide.

13. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and a B-pyrazolidone silver halide developing agent, p-(-methylsulonamidoethyl) phenylhydrazine and 2-benzyl-3- methylisoquinolinium bromide.

14. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of hydroquinone and i-phenyl-Iipyrazolidone silver halide developing agents, pmethylsulfonamidcethyl) phenylhydrazine and 2-benzyl-S-methylisoquinolinium bromide.

15. A photographic developer composition comprising an an aqueous alkaline solution containing a mixture or hydroquinone and 1-phenyl-4,4 dimethyl-3-pyrazolidone silver halide developing agents, p-(,6-methylsulfonamidoethyl)phenylhydrazine and 2-benzy1-3-methylisoquinolinium bromide.

16. A photographic developer composition comprising an aqueous alkaline solution containing a mixture of 'hydroquinone and 1-p-tolyl-4,4dimethyl-S-pyrazolidone silver halide developing agents, p- (-methylsulfonamidoethyl) phenylhydrazine and 2 benzyl-3-methylisoquinolinium bromide.

17. The method of obtaining a direct positive image in a silver halide emulsion layer which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between 1//100 and 1 second and development for 3 minutes at 20 C. in the following internal type developer (Il):

Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulte 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter.

gives a maximum density at least 5 times the 10 maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):

Grams p-Hydroxyphenylglycine 10 Sodium carbonate Water to 1 liter.

and developing only the unexposed portion of said emulsion layer in a developer containing a silver halide developing agent, a hydrazine having the general formula No references cited. 

1. A PHOTOGRAPHIC DEVELOPING COMPOSITION COMPRISING AN AQUEOUS ALKALINE SOLUTION CONTAINING A MIXTURE OF A SILVER HALIDE DEVELOPING AGENT, A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 3-METHYL-3-B-PHENETHYLISOQUINOLINIUM BROMIDE, 2-BENZYL-3-METHYL-ISOQUINOLINIUM BROMIDE, 1-BPHENETHYL-B-PICOLINIUM BROMIDE, 1-B-PHENETHYLQUINOLIUM BROMIDE AND 1-B-PHENETHYL LEPINDINIUM BROMIDE, AND A HYDRAZINE HAVING THE GENERAL FORMULA 